POS0266 EFFECTIVENESS OF A SPACING-UP STRATEGY AFTER ONE-YEAR COURSE OF WEEKLY TOCILIZUMAB IN PATIENTS WITH GIANT CELL ARTERITIS: A SINGLE-CENTRE PROSPECTIVE STUDY
Authors: A. Tomelleri, C. Campochiaro, S. Sartorelli, L. Mariotti, E. Baldissera, M. Matucci-Cerinic, L. Dagna
Journal: Annals of the Rheumatic Diseases (2022)

Background Although tocilizumab (TCZ) is extensively used for the treatment of giant cell arteritis (GCA), there is still uncertainty with regard to optimal treatment duration. The GiACTA open-label extension phase showed that 58% of patients treated with a 12-month course of weekly TCZ had a disease flare in the 2 years following therapy suspension 1 , suggesting that some patients may need a more prolonged duration of this therapy. Objectives To evaluate efficacy and safety of low-dose TCZ maintenance in GCA patients who achieved remission after one year of standard TCZ therapy. Methods GCA patients eligible for TCZ according to the 2018 EULAR recommendations 2 and who achieved remission after one year of weekly subcutaneous TCZ were prospectively enrolled. TCZ was administered every-other-week (EOW) for additional 12 months, and eventually suspended. Patients were evaluated 4-monthly during TCZ therapy, and 1 and 6 months after TCZ suspension (Figure 1). In patients with large-vessel (LV) involvement at baseline, PET scan was performed 12 and 24 months after TCZ start. Primary outcome was relapse-free survival at month 6 since TCZ suspension. Relapse-free survival during TCZ therapy and imaging response at PET scan were also evaluated. Adverse events were recorded. Figure 1. Study design. Results 17 patients were enrolled (12 women, 71%; mean age 71.5±8.7 years). Disease features at diagnosis and TCZ start are listed in Table 1. Reasons for TCZ start were clinical or imaging disease flare (n=9), persistence of disease activity (n=5), and steroid-related adverse events (n=3). At TCZ start, median disease duration was 8 (3-22) months, serum C-reactive protein (CRP) was 13 (6-22) mg/L, daily prednisone (PDN) dose was 25 (15-37.5) mg; 4 patients were already on methotrexate (MTX) which was maintained in 1 of them; 10 patients (59%) had LV involvement on PET scan. At TCZ EOW start, no patient was on PDN and 1 patient was on MTX; MTX was added in another patient due to persistence of LV involvement at PET scan. All patients completed the 24-month TCZ course. Two patients (12%) had a polymyalgic flare while on EOW TCZ: one patient at month 1 and one patient at month 6; of note, one of them had a polymyalgic flare also while on weekly TCZ. Both flares were managed with a PDN course with complete clinical remission. No patient had active LV involvement at 24-month PET scan. Adverse events on EOW TCZ were zoster reactivation (n=1) and neutropenia (n=1). At TCZ stop, no patient was on PDN and 2 patients were on MTX. One month after TCZ stop, all patients were in remission. Six months after TCZ stop, 4 patients (24%) experienced a flare, which was successfully managed in all cases with TCZ weekly re-introduction; in 2 patients, a PDN course was also started. Table 1. Patients’ characteristics at giant cell arteritis diagnosis and at study entry. GCA diagnosis, n=17n (%) TCZ start, n=17n (%) Headache 16 (94) 5 (29) Scalp tenderness 11 (65) 5 (29) Jaw claudication 9 (53) 2 (12) Ocular ischemic manifestations 3 (17) 0 (0) Polymyalgia rheumatica 8 (47) 0 (0) Constitutional symptoms 14 (82) 7 (47) Active vasculitis on PET 10 (59) 10 (59) Modality of diagnosis Vascular ultrasound 7 (47) - Temporal artery biopsy 3 (17) - PET 10 (59) 10 (59) Conclusion In this proof-of-concept study, low-dose TCZ maintenance in GCA showed excellent disease control, which was maintained in most patients after therapy suspension. Longer follow-up and replication in larger cohorts are required. References [1]Stone JH et al. Lancet Rheumatol. 2021 [2]Hellmich B et al. Ann Rheum Dis. 2020 Disclosure of Interests Alessandro Tomelleri: None declared, Corrado Campochiaro: None declared, Silvia Sartorelli: None declared, Letizia Mariotti: None declared, Elena Baldissera Speakers bureau: Prof Lorenzo Dagna received honoraria as a speaker from Roche, Marco Matucci-Cerinic: None declared, Lorenzo Dagna Consultant of: Prof Lorenzo Dagna received consultation honoraria from Roche